Fatty Acid Profile of Sunshine Bass: I. Profile Change is Affected by Initial Composition and Differs Among Tissues

Abstract

Fatty acid (FA) composition of fillet tissue can be tailored by transitioning fish from alternative lipid-based, low long-chain polyunsaturated fatty acid (LC-PUFA) grow-out feeds to high LC-PUFA "finishing" feeds. To address whether grow-out feed composition influences the responsiveness of fillet tissue to finishing, sunshine bass (SB, Morone chrysops x M. saxatilis) were reared to a submarketable size on grow-out feeds containing fish oil (FO) or a 50:50 blend of FO and coconut (CO), grapeseed (GO), linseed (LO), or poultry (PO) oil. For the final 8 weeks of the trial, fish were either maintained on assigned grow-out feeds or finished with the 100% FO feed. Production performance was unaffected by dietary lipid source, but fillet FA profile generally conformed to nutritional history. Regardless of grow-out regimen, finishing had a significant restorative effect on fillet FA composition; however, complete restoration of control levels of 20:5n-3, 22:6n-3, total LC-PUFA and n-3:n-6 FA ratio was achieved only among fish fed the CO-based grow-out feed. Saturated fatty acids (SFA) appear to be preferential catabolic substrates, whereas medium-chain and long-chain PUFA are selectively deposited in tissues. Provision of SFA in grow-out feeds appears to optimize selective FA metabolism and restoration of beneficial fillet FA profile during finishing.

Modulation of selenium tissue distribution and selenoprotein expression in Atlantic salmon (Salmo salarL.) fed diets with graded levels of plant ingredients

“…This highlighted that substitution of marine ingredients by terrestrial plant products leads to a substantial decrease in Se in flesh, reducing the ability of farmed fish to supply an adequate Se dose to human consumers. Therefore, it would be interesting to study the possible restoration of Se content by returning fish to a 'finishing' diet containing higher levels of FM and FO for a period of time before harvest, as has been shown for n-3 LC-PUFA (50)(51)(52) . Alternatively, the supplementation of aquafeeds with organic sources of Se (Se-enriched yeast), less likely to cause toxicity than inorganic sources, could be used as a measure to maintain adequate Se levels in salmon flesh, as shown for several other fish species (53)(54)(55)(56) .…”

Fatty Acid Profiles Distinguish Channel Catfish from Three Reaches of the Lower Kaskaskia River and its Floodplain Lakes

“…The two pulverization/extraction methods provide equivalent results, but freezedrying/grinding is preferred for creating homogenous samples of larger volumes of tissue (i.e., as is typical for fillet samples). Resultant FAMEs were identified and quantified by gas chromatography by reference to external standards (Supelco 37 Component FAME Mix, PUFA-1, and PUFA-3, Supelco, Bellefonte, PA, USA) as described by Trushenski et al (2008). Fatty acid methyl esters were quantified in terms of relative percent area and are reported as g/100g FAME.…”

“…The liver is the main organ for FA metabolism in fish, thereby making a change in dietary FA more quickly apparent in this tissue. Faster apparent turnover time with diet change in liver could also be due to increased triacylglycerol content, which is primarily used for energy storage (Mourente & Bell, 2006) and tends to reflect dietary intake more directly than other lipid types (Trushenski et al, 2008). Conversely, muscle tissue is generally higher in phospholipids (Budge et al, 2011) (an essential component of structural membranes), which preferentially incorporate certain FA (Trushenski et al, 2008), causing them to be generally less responsive to dietary FA than triacylglycerols.…”

“…Faster apparent turnover time with diet change in liver could also be due to increased triacylglycerol content, which is primarily used for energy storage (Mourente & Bell, 2006) and tends to reflect dietary intake more directly than other lipid types (Trushenski et al, 2008). Conversely, muscle tissue is generally higher in phospholipids (Budge et al, 2011) (an essential component of structural membranes), which preferentially incorporate certain FA (Trushenski et al, 2008), causing them to be generally less responsive to dietary FA than triacylglycerols. Differences in responsiveness to dietary FA and in turnover rates suggests that liver tissue might be more relevant for investigating recent habitat switches or changes in diet (e.g., on the scale of weeks), whereas muscle or fin tissue might be expected to reflect shifts in habitat use and diet on a longer time scale (e.g., on the scale of months).…”

“…Studies that have observed faster turnover time in liver FAs include Dave et al (1975), Regost et al (2003), Mourente & Bell (2006), and Zamal & Ollevier (1995). In addition to a faster metabolism, different tissue types have been shown to have preferential metabolism of specific FAs depending on the tissue's initial FA levels relative to the diet (Trushenski et al, 2008;Budge et al, 2011).…”